Method and Apparatus For Welding Cost Calculator

ABSTRACT

A method and apparatus for providing welding-type power is disclosed and includes a cost calculator.

FIELD OF THE INVENTION

The present invention relates generally to the art of welding-type powersupplies and welding operations. More specifically, it relates to awelding-type power supply with a cost calculator built, or to a methodof calculating costs of welding.

BACKGROUND OF THE INVENTION

There are many known welding-type systems used to provide a welding-typeoutput or welding-type power for many known applications. Welding-typesystem, as used herein, includes any device capable of supplyingwelding, plasma cutting, and/or induction heating power includinginvertors, convertors, choppers, resonant power supplies, quasi-resonantpower supplies, etc., as well as control circuitry and other ancillarycircuitry associated therewith. Welding-type output, as used herein,includes outputs suitable for welding, plasma or heating. Welding typepower, as used herein, refers to welding, plasma or heating power.

Examples of prior art welding-type systems include those described inMethod of Designing and Manufacturing Welding-Type Power Supplies,Albrecht, filed Sep. 19, 2001, application Ser. No. 09/956,401, whichissued on Mar. 30, 2004 as U.S. Pat. No. 6,713,721; Pendant Control fora Welding-Type System, L. Thomas Hayes, filed Sep. 19, 2001, applicationSer. No. 09/956,502, which issued on Oct. 28, 2003 as U.S. Pat. No.6,639,182; Welding-Type Power Supply With A State-Based Controller,Holverson et al, filed Sep. 19, 2001, application Ser. No. 09/956,548,which issued on Jun. 8, 2004 as U.S. Pat. No. 6,747,247; Welding-TypeSystem With Network And Multiple Level Messaging Between Components,Davidson et al., filed Sep. 19, 2001, application Ser. No. 09/957,707,which issued on Dec. 30, 2003 as U.S. Pat. No. 6,670,579; Welding-TypePower Supply With Boot Loader, L. Thomas Hayes, filed Sep. 19, 2001,application Ser. No. 09/956,405, which issued on Jan. 7, 2003 as U.S.Pat. No. 6,504,131; and Welding-Type System With Robot Calibration,Rappl et al., filed Sep. 19, 2001, application Ser. No. 09/956,501,which issued on Nov. 4, 2003 as U.S. Pat. No. 6,642,482. Each of thesepatents is hereby incorporated by reference.

It is often desirable to know the cost to weld a component (or a numberof different components). Determining the cost to weld a componentrequires the end user to do a time study, and/or gathering data such asparts per hour, parts per spool of wire, time the operator spendswelding, time loading parts, amount of wire and shielding gas consumed,and electricity used. Gathering such data can be time consuming, costly,and inaccurate.

Moreover, this might need to be done for each welding cell for eachshift and operator. This may also need to be repeated often, asproduction variables may change over time. For example, an operator mayweld a first part fast, but not as efficient at welding a second part,and thus so operator efficiency, weld parameters and spatter generationwill not be the same. Changes in manufacturing procedures may alsoaffect the studies. Efficiencies improve as operators and weld engineershave more experience welding the part. New parts and fixtures are rarelyoptimized for production needs. Over the course of a product lifeimprovements are made to fixtures, operators get more comfortablewelding, weld engineers improve weld parameters, parts are made moreaccurately, etc.

Some systems include sophisticated programming and/or data monitoring.However, that data has generally been used to control the weldingprocess. There remains a need for a welding-type system that includes aneffective way to calculate the cost of a welding operation andefficiencies of welding-type systems, preferably using data from thewelding-type system. Accordingly, a welding-type system that includes acost calculator, or a cost calculator for welding is desired.

SUMMARY OF THE PRESENT INVENTION

According to one aspect of the invention a welding-type system includesa cost calculator that uses data from the welding-type system, includingdata from the weld, to determine the cost of a weld. Other information,such as per unit labor costs, energy costs, material costs, etc., may beused as well.

According to a second aspect a welding cost calculator uses data from awelding-type system, including data from the weld, to determine the costof a weld. The cost calculator may reside in software that is not partof the welding-type system, but preferably works with the welding-typesystem. Other information, such as per unit labor costs, energy costs,material costs, etc., may be used as well.

Other principal features and advantages of the invention will becomeapparent to those skilled in the art upon review of the followingdrawings, the detailed description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a welding-type system in accordance with the preferredembodiment of the present invention;

FIG. 2 is block diagram in accordance with the preferred embodiment ofthe present invention; and

FIG. 3 is a block diagram of a welding cost calculator in accordancewith the preferred embodiment of the present invention.

Before explaining at least one embodiment of the invention in detail itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting. Like referencenumerals are used to indicate like components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention will be illustrated with reference to aparticular welding-type system it should be understood at the outsetthat the cost calculator can be implemented with other welding-typesystems, or as a stand-alone unit, preferably connected to awelding-type system. Cost calculator, as used herein, includes softwareand/or hardware, found in one or more locations, used to calculate thecost of one or more welding processes, or aspects of one or more awelding processes. The cost calculator may be part of a systemcontroller, a separate module of a system, or a stand-alone unit that ispreferably connected to (physically and/or a data connection such asover a network) a welding-type system. The cost calculator may useotherwise available data, or receive data specifically obtained orintended for the cost calculator. Data can be sensed, measured, orobtained from a user input. Module, as used herein, includes softwareand/or hardware that cooperates to perform one or more tasks, and caninclude digital commands, control circuitry, power circuitry, networkinghardware, etc.

The preferred embodiment provides for implementing the invention withthe Miller Axcess® or Miller AxcessE® welding power supply. The Axcess®or AxcessE® can include weld data logging and/or monitoring and/or areal time clock and a cost calculator in the preferred embodiment.

The preferred embodiment provides that the cost calculator automaticallytracks the time required to make a part, the idle time, wire used, gasused and power usage. It also includes an algorithm to determine spatterproduction to generate a percent wire utilization (how much wire isactually on the weld, and how much ended up as spatter on the part orfixture). One such algorithm uses the relationship between the currentwhen the short clears, and spatter. Generally speaking, spatter isresponsive to the square of the current when the short clears. For someprocesses and materials it is proportional, and the constants (K1 and K2in spatter=K1+K2*I*I, where * is multiplied) can be determinedempirically. Alternatives provide for using other functions of current,such as spatter=K1+K2*I, or K3+K2*I+K1+I*I, or other functions of I, ora function of the time in the short relative to the time in the arc,etc.

Alternatives include having user input such as using a PC application, aweb page, or a USB key that allows the user to enter and adjust theircosts for labor, wire, gas, power, etc, or obtain costs dataautomatically via a network, such as from a server. The system uses thisinformation to calculate the costs of welding. This allows the user tofocus on parts/welds that increase or maximize productivity and profits.The calculated cost information may also be used as a measurable numberto justify and/or analyze improvements implemented in a weld cell.

Various alternatives include providing web screen plots showing theoutput of the cost calculator (i.e., cost for various factors for awelding operation). The cost calculator preferably tracks one or moreof: time between parts, part production cycle time, time spent welding,gas usage, wire usage, spatter (estimated), and power usage.

The cost calculator then uses the tracked information to determine timespent welding, time spent loading parts (system on but not welding), gascosts, wire costs (the spatter estimate will help with wire cost).Additional parameters, such as per unit wire cost, per unit energy cost,per unit material cost, etc., can be provided by the user, obtained overa network such as from a server, or input at a later time. Theparameters can be fixed or given ranges, so that as material costs orenergy costs, for example, vary, the cost calculator can determine therelative costs of various parts, and production can be adjusted tomaximize profit.

Alternatives include consumable usage (tips, liner, torch life—estimatedfrom welding current), using a real time clock to account for breaks(when the user is idle for more than a given time). The number of scrapparts can be entered via web page, obtained from a server, or other dataentry method.

The time tracking is preferably obtained through an operator interface.The operator indicates the start of new part in the weld cell and thepart completion. The time could be measured as start of a part to starton next part, end of a part to end of next part or start of anyspecified weld till the start of the next parts specified weld. Theoperator could push a button indicating the start, or the time could beautomated. For example, time could be started based on when a clamp isplaced on a fixture, input from a PLC or robot, current output, etc.

The times that are acquired preferably include total part time (new partto next new part time or part production cycle time), weld time (firstweld of part, till last weld of part), arc on time (total time spentwith the welding arc on), load time (estimate of time spent loadingparts which can be estimated by load time=total part time−weld time),off time (when the welding-type system is not powered up). Thewelding-type system preferably includes a real time clock with batteryback-up so it can maintain time while off, or the welding-type systemhas access to an external source of time. Time off, such as breaks,shift changes, lunch, etc. can be determined by an unusually length timebetween the end of one part and the start of the next, by being tied tothe facilities employee time clock, or by sensing an employee's ID card.

Consumable-related variables include one or more of: wire usage (basedon motor feedback the wire used is measured, but there might be errorsdue to slippage of the drive rolls on the wire and an alternativeprovides for using an external wirefeed speed sensor), an algorithmestimates the amount of spatter produced while welding, which correlatesto grinding time and wire utilization (how much wire ended up in theweld and how much ended up on the floor), gas usage (flow rate may beentered via a web page, from a server, or other data input source, andthe system tracks the time the gas is on to estimate gas usage, analternative includes a gas flow sensor which gives real time feedbackand improved accuracy), and power (estimated by output power of thewelder, times an efficiency factor, and feeder power used by the systemwhile in standby can be included, as well as auxiliary output power (115AC), and an alternative is to sense the primary voltage and current andcalculate based on power factor).

User or system inputs may be obtained using a web interface, from aserver or other network source, wirelessly, or in any other convenientmanner. These inputs include one or more of costs of power, power factorcosts, costs of wire, costs of gas, gas flow rate (if no sensorprovided), operators hourly pay rate (burdened or not) which ispreferably tied to an operator log-in screen, or USB key, employee IDcard, biometrics (fingerprint scanner, e.g.) etc., so as an operatorlogs in the appropriate hourly rate is applied, and/or cost of the partto be welded.

The cost calculator uses log files to track cost by part, shift, day,week, month and/or operator. The cost calculator can determineup-to-date and accurate production costs, benchmark productionimprovements and accurately measure the resulting savings, focus onareas with significant opportunities for cost improvement, allow forflow analysis (determine where a part spends time as it travels along aproduction line), identify long fixture load times vs weld times, whichindicate a fixture or cell layout issues, and allocate the hourly wageof an operator to the part being produced.

Alternatives provide that the cost calculator software that acquires andanalyzes data reside in a computer or controller in the cell, in thefeeder, in the power supply, in a PLC or in a robot. Acquisition of datamay done in the weld cell and then sent to a remote location (networkedcomputer, USB key . . . ) for analysis of cost. The analysis can be donein real time, or after an operation has ended.

Various embodiments provide for using each of the above parameters,additional parameters, or less than all of the above parameters (with orwithout other parameters). For example, one embodiment provides that thecost calculator use part cycle time, arc on time, wire usage, power,costs of power, costs of wire, and operators hourly pay rate todetermine the cost of the part. Another embodiment provides that thecost calculator use part cycle time, weld time, arc on time, wire usage,gas usage, power, costs of power, costs of wire, costs of gas, gas flowrate and operators hourly pay rate to determine the cost of the part.

Referring to FIG. 1, a welding-type system 100 includes a power supply1, and a wire feeder 6, which cooperate to provide power over a pair ofweld cables 2 and 4 to a workpiece 7. Feeder cable 3 and a voltage sensecable 5 are used for control/feedback. The system shown is an Axcess®welding system, but the invention may readily be implemented with otherwelding-type systems. Welding system 100 performs generally as prior artwelding systems, but includes a cost calculator as part of a controller,or as a pc as part of the weld cell.

Referring now to FIG. 2, a diagram shows a welding-type system 200includes an input circuit 202, a power circuit 204, and an output 206,as well as a controller 208 and a user cost input module 212. Circuits202, 204 and 206, and controller 208, are part of welding power supply 1(FIG. 1) in the preferred embodiment. They are distributed over severallocations (such as wire feeder 6, an external control circuit, etc.) inother embodiments. Circuits 202, 204 and 206, and controller 208 arefunctional blocks and need not be physically distinct circuits.

Circuits 202, 204 and 206, are, in one embodiment, consistent with thoseshown in U.S. Pat. No. 6,329,636, entitled Method And Apparatus ForReceiving A Universal Input Voltage In A Welding, Plasma Or HeatingPower Source, issued Dec. 11, 2001, which is hereby incorporated byreference. Accordingly, circuits 202, 204 and 206 may include circuitryto rectify, boost, power factor correct, invert and transform differentinput powers into welding-type power.

Controller 208 includes much of the control circuitry of the prior art,including that used to turn switches on and off circuits 202, 204 and206. This switch control circuitry can be implemented with other controlcircuitry, including digital, analog, and include microprocessors, DSPs,analog circuitry, etc. Also, controller 208 includes cost calculator210. Cost calculator 210 resides primarily in data acquisition hardwareand software implemented on a microprocessor in the preferredembodiment. Alternatives provide for cost calculator 210 to not be partof controller 208, such as external device, such as a pc or pda, locatedin the weld cell or remotely (and communicates with welding-type system100 over a network or dedicated connection).

User cost input module 212 allows for the user to input cost data, suchas material cost, labor cost, and can include quantitative informationsuch as the hours worked, amount of material used, amount of weldingperformed, etc., if such information is not obtained via sensing ormeasurement. User input module 212 includes a data entry device, such asa keyboard in one embodiment, and is a pc or other computing device inanother embodiment. It is linked to cost calculator module 210 via anetwork, (wired or wireless) or via a dedicated connection in variousembodiments. Even if cost calculator 210 is physically within controller208, it may be considered to be not part of controller 208.

Referring now to FIG. 3, a diagram of one embodiment of cost calculator210 includes a time calculator 301, a consumable cost module 302, amaterial cost module 303, and a cost determination module 304. Thevarious blocks represent functional modules that are implemented usingsoftware. One skilled in the art could readily have other functionalblocks, or combine functions in other ways.

Time calculator 301 receives signals indicative of a welding of a partbeing started 306, the arc being on 307, and the power supply being on308. As described above, these times may be derived from the clamp beingplaced on the part, and from power supply 204 and/or controller 208.Time calculator 301 preferably includes a real time clock. From thevarious signals 306-308 and the RTC signal time calculator 301 candetermine the total part time, arc (weld) time, load time, and off timeof welding-type system 100, by noting the RTC time when the varioussignals are received. Alternatives provide for the time to be providedto time calculator 301.

Consumable cost module 302 receives as inputs signals indicative of wireusage 310, power usage 311, and gas usage 312. As described above, wireusage 310 is determined from wire motor feedback or from an externalsensor. Power usage 311 is determined from power output of the welder,times an efficiency factor, feeder power and auxiliary output power (115AC), or by sensing the primary voltage and current and calculate basedon power factor. Gas usage 312 is determined from a user input of flowrate and the time the gas is on, or using a gas flow sensor.

Material cost module 303 receives as inputs the per unit wire cost 314,power cost 315, and gas cost 316. It provides this information toconsumable cost module 302, which uses that and the informationindicative of the quantity of consumables used to calculate consumablecosts. The inputs are preferably from a web page, but could be inputover a network, on a pendant, on a portable storage device such as a USBdrive, or obtained manually or automatically from a server or othernetwork location.

Cost determination module 304 receives data from consumable cost module302, and receives labor cost input 318. The labor cost input ispreferably obtained using the employee ID and a data base, but could befrom web page, over a network, from an employee ID card, on a pendant,USB drive etc., from a server, or other network locations.

Cost determination module 304 outputs that cost to a log or output 320.Output 320 is preferably a web page that is accessible over a network,emailed to a recipient, or displayed in the weld cell. It may also bestored locally, on a hard drive, external drive, USB drive, etc.) forlater retrieval.

Alternatives include cost calculator 210 being implemented with otherfunctional blocks, with other parameters, and located other than incontroller 208.

Various alternatives provide that welding-type system 100 includesnetwork communication, such as WAN, LAN, over power lines, over a smartgrid, and that the data transmitted and/or stored, such as on a usbdrive, include arc parameters and primary information, such as harmonicsdata, utilization data, etc. The information can be shared over thenetwork or using a drive with end users, power companies, manufacturersthat use welders, manufactures that supply welders, etc. Additionally,various alternatives and arrangements are shown in the attachedappendix.

Numerous modifications may be made to the present invention which stillfall within the intended scope hereof. Thus, it should be apparent thatthere has been provided in accordance with the present invention amethod and apparatus for a welding-type system with a cost calculatorthat fully satisfies the objectives and advantages set forth above.Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

1. A welding-type system, comprising: a source of welding-type power; acontroller, including a control output connected to the source ofwelding-type power; and a cost calculator, connected to the controller.2. The welding-type system of claim 1, further comprising a user costinput module, connected to provide data to the cost calculator.
 3. Thewelding-type system of claim 2, wherein the cost calculator includes amaterial cost module connected to receive data from the user cost inputmodule, and a cost determination module connected to the material costmodule.
 4. The welding-type system of claim 3, wherein the costcalculator further includes a time calculator connected to the costdetermination module.
 5. The welding-type system of claim 2, wherein thecost calculator includes a time calculator, and includes a costdetermination module connected to the user input cost module andconnected to the time calculator.
 6. The welding-type system of claim 5,wherein the cost calculator includes a consumable cost module connectedto receive data from the user cost input module, and connected to thecost determination.
 7. The welding-type system of claim 4, wherein thecost calculator includes a consumable cost module connected to receivedata from the user cost input module, and connected to the costdetermination.
 8. The welding-type system of claim 2, wherein the costcalculator includes a consumable cost module connected to receive datafrom the user cost module, and a cost determination module connected toconsumable cost module.
 9. The welding-type system of claim 8, whereinthe user cost module is connected to the consumable cost module over anetwork.
 10. The welding-type system of claim 2, wherein the user costmodule includes software residing on a personal computer.
 11. A methodof providing welding-type power, comprising: receiving input power andconverting it to welding-type power; controlling the converting; andcalculating at least one aspect of the cost of performing a weld. 12.The method of claim 11, further comprising receiving from the user costdata related to the at least one aspect, and using that cost data in thecalculating.
 13. The method of claim 12, wherein the at least one aspectincludes material costs and receiving includes receiving from the usercost data related to materials.
 14. The method of claim 13, wherein theat least one aspect further includes labor costs, and receiving includesreceiving from the user cost data related to labor.
 15. The method ofclaim 12, wherein the at least one aspect includes labor costs, andreceiving includes receiving from the user cost data related to labor.16. The method of claim 15, wherein the at least one aspect furtherincludes consumable costs, and receiving includes receiving from theuser cost data related to consumables.
 17. The method of claim 13,wherein the at least one aspect further includes consumable costs, andreceiving includes receiving from the user cost data related toconsumables.
 18. The method of claim 12, wherein the at least one aspectfurther includes consumable costs, and receiving includes receiving fromthe user cost data related to consumables.
 19. The method of claim 18,wherein receiving includes receiving data over a network.
 20. A systemfor providing welding-type power, comprising: means for receiving inputpower and converting it to welding-type power; means for controlling theconverting, connected to the means for converting; and means forcalculating at least one aspect of the cost of performing a weld,connected to the means for controlling.
 21. The system of claim 20,further comprising means for receiving from the user cost data relatedto the at least one aspect, connected to the means for calculating. 22.The system of claim 21, wherein the at least one aspect includesmaterial costs and the means for receiving receives from the user costdata related to materials.
 23. The system of claim 22, wherein the atleast one aspect further includes labor costs, and the means forreceiving receives from the user cost data related to labor.
 24. Thesystem of claim 21, wherein the at least one aspect further includeslabor costs, and the means for receiving receives from the user costdata related to labor.
 25. The system of claim 24, wherein the at leastone aspect further includes consumable costs, and the means forreceiving receives from the user cost data related to consumables. 26.The system of claim 23, wherein the at least one aspect further includesconsumable costs, and the means for receiving receives from the usercost data related to consumables.
 27. The system of claim 21, whereinthe at least one aspect further includes consumable costs, and the meansfor receiving receives from the user cost data related to consumables.28. The method of claim 21, wherein the means for receiving is connectedto a network.